That's the match ball for Theo, then. From his own half, Perez plays a brilliant ball down the left for Sanchez. He draws in two Southampton defenders as he reaches the edge of the box and casually awaits for Walcott to arrive. When he does, the pass to his feet is perfect and he coolly slots home for his third.

Another fine goal from Arsenal and Southampton are done here. Oxlade-Chamberlain is again involved, picking out Sanchez who jinks his way down the byline before arrowing a pinpoint cross into Walcott who drives home into the far corner. Easy.

Brilliant from Arsenal. They ping the ball around brilliantly as they advance into the final third with the Perez and Welbeck again combining neatly on the edge of the box. The Spaniard's ball finds Welbeck who opts to slide the ball across goal from a tight angle for Walcott, who taps home with Sam McQueen nowhere to be seen.

Josh Sims looks to be Southampton's best chance of pulling something back here. He harries Holding and wins the ball back 25 yards out from his own goal with Saints eventually winning a free kick as a result of his hard work.

Ospina was almost caught out a moment ago, but he's started to make up for it with a decent save to deny Shane Long. Martina picks out his striker with a brilliant ball curled down the right channel, with the Ireland international smashing his effort towards the near post only to be denied by the Arsenal 'keeper.

Brilliant from Danny Welbeck. Oxlade-Chamberlain picks out his run with a superb 40-yard pass, floating it over Gardos' head and right out the outstretched boot his his teammate. Welbeck keeps his cool and slots it under the onrushing Lewis; his second of the game.